Here's my take on which flag goes where. They've been changing it a bit over the last few months so please don't take this for certain.

- **Closure / Duplicate** → [close vote review queue][1], never to a moderator
- **Spam / Offensive** → moderator queue
- **Very Low Quality** → moderator queue and [low quality review queue][2]
- **Not an Answer** → moderator queue
- **Other** → moderator queue

The items in the low quality review queue are determined automatically based on some heuristics, plus low quality flags by others. 

Note that "very low quality" really should only be used for posts that are unsalvageable due to broken formatting, garbage content, et cetera. Meaning, they should be deleted right away. Anything else most likely falls under some close reason, so please use that instead. Closing questions is something the community can handle on its own—no moderator needed to intervene.


  [1]: http://superuser.com/review/close
  [2]: http://superuser.com/review/low-quality-posts